under a vehicle without first supporting it with jack stands. a hydraulic jack can have external and…

under a vehicle without first supporting it with jack stands. a hydraulic jack can have external and internal leaks. an external leak means the hydraulic oil is leaking to the outside of the jack. external leaks are easy to identify because hydraulic oil will be found on the out side of the jack. the major cause of external leaks is worn piston o - ring and/or worn piston. internal leaking means the hydraulic oil leaks inside the jack, from the pressure chamber to another low pressure area. this type of leak is evident by the self dropping of the weight supported. this is often caused by a leaking release valve. identifying a leaking hydraulic jack - observe the outside of the jack for signs of relative fresh (moist) oil. the most common leak points are the piston o - ring, the release valve and the pumping valve. you can identity the severity of the leak by observing how much oil is on and underneath the jack. an excessive quantity and fresh oil on and underneath the jack where it is stored means there is severe leak and the jack should be removed from service. a small amount of old, dry accumulated oil near the piston however is considered normal, since the o - rings cannot completely prevent oil from going to the outside of the jack. - to test for internal leakage, you can try to jack up some load with the jack in question. wait for 20 minutes, observing how much height the jack has lost. for a normal functioning jack, the height drop should be almost imperceptible. if the jack drops significantly and there is no obvious leaks on the outside then it is most like caused by a leaking release valve. important: the load youre jacking during this test should be stable; with a back - up support in place, to prevent the load from falling, should the jack suddenly fail. why is it important to use a backup support when testing a jack you suspect has an internal leak. should the jack youre testing for an internal leak fail, the backup will keep the load from falling. should the jack youre testing for an internal leak fail while your under the load, the backup will keep you from being crushed.

under a vehicle without first supporting it with jack stands. a hydraulic jack can have external and internal leaks. an external leak means the hydraulic oil is leaking to the outside of the jack. external leaks are easy to identify because hydraulic oil will be found on the out side of the jack. the major cause of external leaks is worn piston o - ring and/or worn piston. internal leaking means the hydraulic oil leaks inside the jack, from the pressure chamber to another low pressure area. this type of leak is evident by the self dropping of the weight supported. this is often caused by a leaking release valve. identifying a leaking hydraulic jack - observe the outside of the jack for signs of relative fresh (moist) oil. the most common leak points are the piston o - ring, the release valve and the pumping valve. you can identity the severity of the leak by observing how much oil is on and underneath the jack. an excessive quantity and fresh oil on and underneath the jack where it is stored means there is severe leak and the jack should be removed from service. a small amount of old, dry accumulated oil near the piston however is considered normal, since the o - rings cannot completely prevent oil from going to the outside of the jack. - to test for internal leakage, you can try to jack up some load with the jack in question. wait for 20 minutes, observing how much height the jack has lost. for a normal functioning jack, the height drop should be almost imperceptible. if the jack drops significantly and there is no obvious leaks on the outside then it is most like caused by a leaking release valve. important: the load youre jacking during this test should be stable; with a back - up support in place, to prevent the load from falling, should the jack suddenly fail. why is it important to use a backup support when testing a jack you suspect has an internal leak. should the jack youre testing for an internal leak fail, the backup will keep the load from falling. should the jack youre testing for an internal leak fail while your under the load, the backup will keep you from being crushed.

Answer

Brief Explanations:

The text states that when testing a jack suspected of having an internal leak, the load should have a backup support in place. This is because if the jack fails during the test, the backup will prevent the load from falling and causing harm, such as crushing someone who might be under the load.

Answer:

Should the jack you're testing for an internal leak fail, the backup will keep the load from falling. Should the jack you're testing for an internal leak fail while you're under the load, the backup will keep you from being crushed.